com.caucho.db.sql
Class Expr

java.lang.Object
  com.caucho.db.sql.Expr

Direct Known Subclasses:

ExistsEvalExpr, FunExpr, GroupResultExpr, SubSelectEvalExpr, SubSelectExpr

public abstract class Expr
extends java.lang.Object

Field Summary

static int	FALSE
protected static L10N	L
static int	TRUE
static int	UNKNOWN

Constructor Summary

Expr()

Method Summary

protected Expr	bind(Query query)
long	cost(java.util.ArrayList<com.caucho.db.sql.FromItem> fromList) Returns the cost based on the given FromList.
com.caucho.db.sql.Order	createOrder(int index) Returns the order.
int	evalBoolean(QueryContext context) Evaluates the expression as a boolean.
long	evalDate(QueryContext context) Evaluates the expression as a date.
double	evalDouble(QueryContext context) Evaluates the expression as a double.
void	evalGroup(QueryContext context) Evaluates aggregate functions during the group phase.
long	evalLong(QueryContext context) Evaluates the expression as a long.
java.io.InputStream	evalStream(QueryContext context) Evaluates the expression as a string.
java.lang.String	evalString(QueryContext context) Evaluates the expression as a string.
int	evalToBuffer(QueryContext context, byte[] buffer, int offset) Evaluates the expression to a buffer
protected int	evalToBuffer(QueryContext context, byte[] buffer, int off, int columnType) Evaluates the expression to a buffer
void	evalToResult(QueryContext context, SelectResult result) Evaluates the expression, writing to the result stream.
com.caucho.db.sql.RowIterateExpr	getIndexExpr(com.caucho.db.sql.FromItem fromItem) Returns an index expression if available.
java.lang.String	getName() Returns any column name.
int	getSQLType() Returns the column type.
Table	getTable() Returns the table.
java.lang.Class	getType() Returns the expected result type of the expression.
void	initGroup(QueryContext context) Initializes aggregate functions during the group phase.
boolean	isBinaryStream() Returns true if the expression returns a binary stream.
boolean	isBoolean() Returns true if the expression returns a boolean.
boolean	isDouble() Returns true if the expression returns a double.
boolean	isLong() Returns true if the expression returns a long.
boolean	isNull(QueryContext context) Returns true if result is null
boolean	isSelect(QueryContext context) Returns true if the expression selects the row.
void	splitAnd(java.util.ArrayList<Expr> andProduct) Splits the expr into and blocks.
long	subCost(java.util.ArrayList<com.caucho.db.sql.FromItem> fromList) Returns the cost based on the given FromList.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

L

protected static final L10N L

UNKNOWN

public static final int UNKNOWN

See Also:

Constant Field Values

FALSE

public static final int FALSE

See Also:

Constant Field Values

TRUE

public static final int TRUE

See Also:

Constant Field Values

Constructor Detail

Expr

public Expr()

Method Detail

bind

protected Expr bind(Query query)
             throws java.sql.SQLException

Throws:

java.sql.SQLException

getType

public java.lang.Class getType()

Returns the expected result type of the expression.

isLong

public boolean isLong()

Returns true if the expression returns a long.

isDouble

public boolean isDouble()

Returns true if the expression returns a double.

isBoolean

public boolean isBoolean()

Returns true if the expression returns a boolean.

isBinaryStream

public boolean isBinaryStream()

Returns true if the expression returns a binary stream.

getName

public java.lang.String getName()

Returns any column name.

getSQLType

public int getSQLType()

Returns the column type.

getTable

public Table getTable()

Returns the table.

splitAnd

public void splitAnd(java.util.ArrayList<Expr> andProduct)

Splits the expr into and blocks.

cost

public long cost(java.util.ArrayList<com.caucho.db.sql.FromItem> fromList)

Returns the cost based on the given FromList.

subCost

public long subCost(java.util.ArrayList<com.caucho.db.sql.FromItem> fromList)

Returns the cost based on the given FromList.

getIndexExpr

public com.caucho.db.sql.RowIterateExpr getIndexExpr(com.caucho.db.sql.FromItem fromItem)

Returns an index expression if available.

createOrder

public com.caucho.db.sql.Order createOrder(int index)

Returns the order.

isNull

public boolean isNull(QueryContext context)
               throws java.sql.SQLException

Returns true if result is null

Parameters:

rows - the current database tuple

Returns:

true if null

Throws:

java.sql.SQLException

isSelect

public boolean isSelect(QueryContext context)
                 throws java.sql.SQLException

Returns true if the expression selects the row.

Parameters:

rows - the current database tuple

Returns:

the boolean value

Throws:

java.sql.SQLException

evalBoolean

public int evalBoolean(QueryContext context)
                throws java.sql.SQLException

Evaluates the expression as a boolean.

Parameters:

rows - the current database tuple

Returns:

the boolean value

Throws:

java.sql.SQLException

evalString

public java.lang.String evalString(QueryContext context)
                            throws java.sql.SQLException

Evaluates the expression as a string.

Parameters:

rows - the current database tuple

Returns:

the string value

Throws:

java.sql.SQLException

evalLong

public long evalLong(QueryContext context)
              throws java.sql.SQLException

Evaluates the expression as a long.

Parameters:

rows - the current database tuple

Returns:

the long value

Throws:

java.sql.SQLException

evalDouble

public double evalDouble(QueryContext context)
                  throws java.sql.SQLException

Evaluates the expression as a double.

Parameters:

rows - the current database tuple

Returns:

the double value

Throws:

java.sql.SQLException

evalDate

public long evalDate(QueryContext context)
              throws java.sql.SQLException

Evaluates the expression as a date.

Parameters:

rows - the current database tuple

Returns:

the double value

Throws:

java.sql.SQLException

evalToResult

public void evalToResult(QueryContext context,
                         SelectResult result)
                  throws java.sql.SQLException

Evaluates the expression, writing to the result stream.

Parameters:

result - the output result

Throws:

java.sql.SQLException

evalStream

public java.io.InputStream evalStream(QueryContext context)
                               throws java.sql.SQLException

Evaluates the expression as a string.

Parameters:

rows - the current database tuple

Returns:

the string value

Throws:

java.sql.SQLException

evalToBuffer

public int evalToBuffer(QueryContext context,
                        byte[] buffer,
                        int offset)
                 throws java.sql.SQLException

Evaluates the expression to a buffer

Parameters:

result - the result buffer

Returns:

the length of the result

Throws:

java.sql.SQLException

evalToBuffer

protected int evalToBuffer(QueryContext context,
                           byte[] buffer,
                           int off,
                           int columnType)
                    throws java.sql.SQLException

Evaluates the expression to a buffer

Parameters:

result - the result buffer

Returns:

the length of the result

Throws:

java.sql.SQLException

initGroup

public void initGroup(QueryContext context)
               throws java.sql.SQLException

Initializes aggregate functions during the group phase.

Parameters:

context - the current database tuple

Throws:

java.sql.SQLException

evalGroup

public void evalGroup(QueryContext context)
               throws java.sql.SQLException

Evaluates aggregate functions during the group phase.

Parameters:

context - the current database tuple

Throws:

java.sql.SQLException